I have a 40 " Mitsubishi here that just went black yesturday. Everything was fine except for a 4-5" line in the top right corner. A little while later the top 6" of the screen was covered in white lines about 1/4" apart running horizontally. Came back about an hour later and there is good sound just a black screen. I can see down inside the top of the unit through vents and clearly see a faint glow at the rear of the picture tube. I have tried messing with the control panel out front but still can't get anything on the screen. I am a novice when it comes to electronics. I can make repairs to some devices with good outcomes. I just need an idea on what to look for when I open this thing up. I don't want to go in totally blind. Any ideas on what to look for?